gaynor



June 19, 1928.

A. C. GAYNOR ET AL ELECTRIC BELL Filed oet. s, 192s Mh 6. @ay/vorPatented June 19, 1928.

UNIT-ED STATES PATENT OFFICE.

ARTHUR C. GAYNOR AND EDWIN G. GAYNOR, OF STRATFORD, CONNECTICUT; SAID IEDWIN G. GAYNOR ASSIGNOR TO SAID ARTHUR C. GAYNOR. i

' ELECTRIC BELL.

*Application filed October 9, 1923. Serial No. 667,475.

This inventiony relates to an electric bell and, more particularly, to abell of simplified construction capable of being operated efficiently byeither direct or alternating current. l

Accordingly, an object of our present invention is to provide a bell orgong operating mechanism in which the losses of electric energy due toeddy currents and other losses associated with the use of alternatingcurrents may be decreased or eliminated.

Another object of the invention is to provide a bell in wliicha maximumnoise may be generated from a given gong with a mini mum of electricity.

Other objects are, to 'provide a bell in `which as much electric energyas possible is taken from the source, Iconverted into the kinetic energyof the-hammer, and in turn imparted to the gong with the least Vpossibleloss Vof energy in impact.. Further objects of the invention are toprovide improved contact means in an electric bell by which the electriccurrent is tapped for a maximum time, of an electromagnet core of highpermeability and a supporting frame in which eddycurrents are reduced toa minimum. Additional objects of the invention are to provide animproved and simple type of hammer and arm, and a supporting base ofsimple and inexpensive construction.

lVith these and other objects in view, the invention comprises the belland actuating mechanism disclosed and set forth in the followingspecification and claims.

The various features of the invention are illustrated in theaccompanying drawings in which;

Fig. 1 is a plan view, partly in section, of a bell embodying apreferred form of the invention the gong being illustrated inV dot anddash lines,

Fig. 2 is alongitudinal sectional view of the bell, taken on line 2 2 ofFig. 1,

Fig. 3 is a longitudinal sectional view of a portion of the bellactuating mechanism taken on line 3 3 of Fig. 1, y

Fig. 4 is a perspective view of the hammer actuating mechanism,

Fig.` 5 is a perspective view of a supporting frame for the hammeractuating mechanism, and n v u Fig. 6 isa detail view of a spring foractuating the hammer of the bell."

In the present invention, the striking portion of the hammer is carriedon an arm that is substantially rigid and linflexible under `the impactsand impulses of the actuating mechanism so that the loss of energy inbending or flexing this arm is eliminated or reduced to' a minimum. Thisarm is pivoted at one end on a supporting frame .which also supports theactuating electrovthe electromagnet, the circuit is closed through astationary contact supported on an insulated spring and a contactmounted on a leaf spring on the hammer arm positioned to press againstand slightly displace the stationary contact when the arm is thrown awayfrom the electromagnet. A sliding contact is thus provided therebyinsuring a clean, effective contact and a period of contact ofconsiderable length. This enables the electric current to pass throughthe electromagnet and to act on the hammer arm for a maximum portion ofthe period of vibration or oscillation. This arrangement also provides aver stron impulse of restitution or reboun whic throws the hammer awayfrom the gong immediately after the stroke and thus prevents a dampeningeffect of the hammer on the gong. A high eficiency of theelectromagnetic action is obtained by making the core of theelectromagnet of a laminated structure and of metal of high permeabilityand by so slitting the supporting frame as to eliminate eddy currentsthus'avoiding loss of energy.

Referring more particularly to the accompanying drawings, the actuatingmechanism embodying the invention is illustrated in connection with agong 10 mounted on a base 12 of suitable construction. Theactuatingmechanism is contained within a cover The elements of the belloperatin mecha- 21 and is held in placeiat one end against this Wall bymeans of a core 22 of an electro-magnet 24 mounted on the back of theframe and spanning the distance from `the back of the frame to theopposite or side wall 25 of the` cover and at the other end by anindentation 26 in a wall 27 of the cover. The frame 20 yis formed of asheet of metal,

. preferably brass, stamped to form a back plate 28 to the upper wall ofthe cover and portion or supporting plate 28, on which the core'22 ismounted, a number of upper side members 29, lower side members 30 andspacing lugs'32 and 34 extendingfrom the tothe base respectively. Thefront edges VV.of the side members 29 and 30 notched to receivea frontplate or slab of insulating material 36. notched to fit into the notchesof the side plate. VThe frame is shaped and adapted to lit Vinto thefront part ofy the f coveinvith the slab 36 against the wali 2l .i andheld tightly inposition against the.V front wall of the Acover by meansof the electromagnettcore 22inounted,on. the rear face of theback 28ofthe trame andby the yindentaf tion 26. Y

with the gong'by asuitable spi'in heavy sheet metal, the hammer beingpressed into the desired cone shape in the stamping operation in whichthe arm is formed. 'A

`..pair of pintles 46 are `formed as the. arm is stamped out to extendsidewise from the opposite end of the arm 42 and be journalled innotches 48 inthe lugs 38 and 40. These pintles may beV easily, insertedinto the notches when the Vframe is out of the cover and .are heldinlposition in the notches by the vside walls of the cover when theframe is inserted in the cover.

The arm 42 is intermittently vibrated to fcausethe hammer 44 to strikethe gong 10 when vthe electro-magnet24and core 22 are energized and rtobe thrown out of contact g device when the energization of theelectro-magnet is interrupted. This spring device is preferably formedof a flat or leaf spring 48 having a hooked end portion 5() adapted tobe in' sorted in a notch '52 inthe endof the plate 2Ol andfreturn overtheopposite face of the plate.V The free end of the spring extendstowards the arm 42 and presses thereagainst When the electro-magnet 24is energized,

it attracts the` arm 42V directly; 'causing it to swing on the pivotingpintles 46 and causing the hammer 44 to strike the inner surfaceelectro-magnet is exerted on the arm 42 at a locality intermediate thepivotal point and Y at a locality adjacent the electro-magnet core nisinare mounted principally on a rame 20, 22 which fits in the coveradjacent aside wall of the' gong l0. The attractive force of theflexible, a considerable portion of the force Y Vof theelectro-magnet.wouldbe exerted in flexing the arm before this forcewould be transmitted to the hammer. This lag in the transmission of theimpelling 4force tothe hammer would, in addition tend to holdthe hammerin contact with the gong after the Vimpact and thus tend to dampen thevibration of the gong, and deaden the sound. Y

To obtain the maximum Veiiiciency inthe utilization kof theelectro-magnetic force generated in theelectro-magnet, therefore,

the arm 42 is. made substantially'V rigid so that it suffers nosubstantialjflexing under force promptly and Y undiniinished to -thehammer 44, while at the same time permitting the returning forceV of thespring 48 to strengthen tlie'reboundiof the hammeras it strikes the(gong and thus immediately throw it outv of contact with the' surfaceofthe` gong.V By makingthe arin 42 of the reV `quired stiffness,therefore, the foices of the electromagnet and of the springr4'8` are aseectiveasthough they acted directly on rthe,

hammer 44.

l The current for energizingi'th, electro-y magnet is supplied from asupply main v54 to a binding post 56, Vwhich isconnected to theelectro-magnet 24 by means of aconducthe forces exerted onV it andtransmits this.

lao

tor wire 58. From the electro-magnet 24,

the current is returned through a conductor.

60 to a AContact snpperting member 62 mounted on the plate of insulating`material.

36Y and insulated from thel cover V14. Y A spring 64 is mounted on thearm 42 to extend toward the contact supporting member 62 and is providedatfits free end with a contact 66 adapted to contact with'v a stationarycontact v68 mounted on the member 6221s the spring 48 swings the yarm 42away from the electrofinagnet 24. VWhen the contacts 66 and'68 are inVcontact the Vcurrent returns through the spring v64 to vides a spring or resilient support for thev Contact 68 so that it is ydisplacedslightly bythe pressure of the spring 64. The ydis- V placement of theContact 68'depends von the force withwhich the arm 42V is thrown backVand forth, thus affordingra'self adjusting les we 'Y support for thecontact 68 that enables the usual type of adjusting screw to bedispensed with. The displacement of the contacts also causes a slightsliding between the contacts that keeps the contact surfaces clean andinsures a contact. By means of this yielding contact, moreover, thecontacts are in contact withv each other for a longer portion of theperiod of vibration and a larger quantity of current can be tapped froma given source. The contact support 62 is preferably formed of aU-shaped piece of metal 74 secured to the insulating plate 36 and theconductor 60 by means of a rivet 76.

To increase the efficiency in transforming the electric energy of thecurrent flowing through the coil 24 into magnetic force aeting on thehammer arm 42, the core 22 is made of a laminated structure and of ahighly permeable metal. This is preferably done by bending a strip ofpermeable metal of the proper size into folds extending longitudinallyof the core and pressing these folds together into close contact, at thesame time giving the folded mass an outer cylindrical shape as the foldsare compressed together. As this operation may be carried out equallywell with metals of different properties, no difficulty is experiencedin making the core of a metal of high permeability. The core is mountedon the plate 28 of the frame 20 by inserting its end in a hole 7 8 inthe plate. The compressibility of the laminated core aids materially inreadily effecting a tight lit of the core in the hole 78 in the plate20. The plate is slit at 80 from the hole 7 8 to the end of the plate tobreak the electric circuit through the plate about the core and thuseliminate eddy currents about the plate as the magnetism through thecore varies or is reversed in the case that alternating currents areused. The slit 80 also permits the hole to be very slightly enlarged byspreading the slit and to contract on the end of the core 22 insertedtherein and thereby provides a resilient and gripping hold on the core.v

The gong and gong operating mechanism may, of course, be mounted on anysuitable base. The present invention, however, provides a base ofparticularly cheap, simple and durable construction byl stamping thebase of sheet metal and stamping a supporting post for the gong at thetime that the base is stamped out. This is done by bending the portion82 beneath the gong upwardly at a right angle to the main portion of thebase and extending it horizontally to form a fiat lug 84 on which thegong l0 may be mounted by means of a rivet or bolt.

As changes of construction could be made within the scope of ourinvention, it is intended that all matter contained in the abovedescription or shown in the accompanying drawings shall be interpretedas illustrative and not in a limiting sense.

Having described the invention, what we .claim and desire to secure byLetters Patent 1s:

1. A device of the type described which comprises, an electromagnetcore, and a base plate having a hole in which the end of said core isreceived and having a slit extending from said hole to the edge of saidplate, permitting said hole to contract onto and hold the inserted endof the core.

2. A device of the type described which comprises, a casing, a framemounted in said casing having a iiat plate extending longitudinally ofsaid casing and side walls, and a notch in the end of each side wallparallel to said plate, a vibrating arm having a pair of pintles pivotedin said notches and held in place by the adjacent wall of the casing, aleaf spring bent through a notch in and gripping said plate and pressingagainst said arm, and an electro-magnet on the opposite side of saidplate.

3. An electric bell which comprises, a casing, a frame in said casingfitting against one side and the adjacent walls of said casing, anelectro-magnet extending from said frame to the opposite wall of saidcasing holding one end of said frame in position, and an inwardindentation positioned in an adjacent side wall to retain the adjacentend of said frame in position.

4. A device of the type described which comprises, a frame, a vibratingarm pivoted at one end of said frame, and a. leaf spring pressingagainst said arm and having a hooked end engaged about the end of saidframe, a covering casing for said frame and acting to hold said springin position.

ARTHUR C. GAYNOR. EDWIN G. GAYNOR.

